Locomotive-spbing



H. MCDOUGAL..

LOCOMOTIVE SPRING.

APPLlcMmN FILED MAY29.1919.

3Q l '7 98 Patented Nov. 11, 1919.

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i LOCMOTIVE-SPRING.

Specification of Letters Patent.

ratentcd Nov. 11, 191e.

Application filed May 29, 1919. Serial No. 300,784.

To all whom it may concern.'

Be it known that l, ROBERT McDoUeALL, citizen of the United States ofAmerica, residing at Jacksonville, in the county of Duval and State ofFlorida, have invented new and useful Improvements inLocomotive-Springs, of which the following is a specification.

Ilhe object of the invention is to provide a spring of the leaf typedesigned especially for use in connection with locomotives and similarheavy vehicles, wherein any desired number of coperating elements may beemployed and may be securely held in proper relative positions withoutinvolving the puncturing or perforating of said elements and hencewithout detracting from the strength thereof or impairing the durabilityof the same, and to this end the invention consists in a construction,combination and relation of parts hereinafter specifically set forth, itbeing understood that changes in form, proportion and details may beresorted to within the scope of the claims without departing from theprinciple involved.

In the drawing:

Figure 1 is a side view of a spring and mounting e1nb0dyi11g--theinvention.

Fig. 2 is a transverse section of the same on the plane indicated by theline 2 2 of Fig. l.

Fig. 3 is a detailed view in perspective of the clamp or chair in whichthe elements or leaves of the spring are seated and held.

Whereas in the ordinary leaf spring construction it is common to employone or more bolts disposed at or near the center of the structure forthe purposeof maintaining the registration and proper relation of theparts, it is the purpose of the present invention to insure a uniformand permanent relation under all conditions of use and strain withoutdiminishing the transverse strength or resistance to fleXure, but on theother hand to provide a means for maintaining the desired relation undersuch conditions as to increase the resistant qualities of the leaves andto graduatev the resistant effect in accordance with the relativelengths of the leaves to the end that a maximum efficiency of thestructure may be attained.

Obviously when7 as in the ordinary practice a nine-leaf spring isemployed in connection with a locomotive truck there is a wide di'erencebetween the lengths of the lower-most and uppermost elements, and hencein order to secure the most eflicient cooperation it desirable thatthere should be a similar graduation of the be. ring relations of theelements with reference to the chair or other supporting member, andhence in the present instance there is provided in the chair l0 a base11 having a transverse rounded bearing rib 12 for reception by acorrespondingly rounded offset in the lowermost leaf member 13 and thesuperposed leaf members are provided with corresponding offsets whichnest uniformly and hence increase in extent from the lowermost to theuppermost leaf so that the oifsets in all of the several elements of thespring are concentrically disposed` This arrangement in volves an offsetla in the uppern'iost spring leaf which measures longitudinally of thespring proportionate to the difference in the length of the uppermostleaf as compared with the lowermost leaf, and the offset portions of theseveral leaves are held in this nested concentric relation by means of.transverse retaining pins 16 which connect the arms 17 forming the sidewalls of the chair, said arms of each wall being diyer' gently relatedso as to seat said retaining pins or bolts at the points of mergence ofthe offset 214i; with the flat or body portion of the leaf. Obviouslythe anchoring of the uppermost leaf serves by reason of the intin'iatenesting of the offsets of the several leaves to effectively lock thelatter in their proper relation with the lower-most leaf and hence thelatter with the transverse rib of the seat in the chair.

In Hexure this arrangement results in a distribution of the strain, andvaries the point of maximum bend according to the length of the leaf, sothat the maximum eiliciency of each element is utilized with a corresponding reduction in the tendency to cause fracture.

1What is claimed ifsl. A. plural leaf spring having leaves of graduatedlengths provided at their centers with rounded offsets arrangedconcentricall y in nested relation, in combination with a chair having arounded hearing rib in engagement with the offset of the leaf of mininmuni lengtl1, and provided with spaced retaining pins 1n engagement withthe leaf of maximum length at the points of mergence of its offset withthe body portions of the leaf.,

2. Aplural leaf spring` having its elements nected by transverseretaining pins in enpro'vided at their Centers with transverse gagementwith the surface of the leaf of concentrieally nested osets, incombination maximum length at the limitsl of the oset 10 with a chairhaving its seat provided with portion of said leaf.

a transverse rounded bearing rib in engage- In testimony whereofI I aIXmy signature. ment With the o ffset of the leaf of minimum length, andhaving divergent side arms con- ROBERT MGDOUGALL.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

. Y Washington, D. C.

